Since you are asking about special balancing issues I think you have already been told or have done some searching yourself.

Quote:

CRANKS
350 - The crank for the LT1 looks just like the one in the late 350 and has the same casting number 14088526, but it’s balanced for the lightweight pistons that were installed in the LT1. Be sure to keep these cranks separate so they don’t end up in a regular 350, and don’t ever use a regular 350 crank in a LT1. In fact, if you are short of LT1 cranks and don’t have a balancing machine in your shop, you would be better off using a crank from a 305 instead of a 350 because it’s actually closer to the balance specs for the LT1 crank.

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Tim

"Heavy" beer is for wine drinkers that are too embarrassed to drink wine in front of their buddies. "Light" beer is a drinkin' man's beer!